Internal-combustion motor



Febu l1, 1930.

L. DUFOUR INTERNAL COMBUSTI ON MOTOR Filed Jan. 12, 1927 Patented Feb.lli, 1930 PATENT OFFICE LEON DUFOUR, or vERsoIx, SWITZERLANDINTERNAL-COMBUSTION MOTOR Application led January 12, 1927, Serial No.160,744, and. in Germany-Ianuary, 1926.

The present invention relates to internal combustion engines and moreparticularly to engines of the two cycle trunk piston type.

It is a well known fact that an efficient means for increasing theoutput of an internal combustion engine consists in cooling the pistonto the utmost.' y It is an object of the invention to provide a twocycle internal combustion engine with means for cooling the piston bythe circulation of the combustible mixture through the piston and forthis purpose the piston cemprises a passage arranged to conduct thecombustible mixture into the interior thereof to beneath the piston headbefore entering the crank ease, "this passage being arranged in such away so as not to obstruct the oscillating movement of the piston rod.

The invention is illustrated in the accompanying drawing in which:

Fig. 1 is a vertical section of a two cycle internal combustion engine,the section being taken through the inlet and exhaust ports of thecylinder. l

Fig. 2 is'a' central, vertical section drawn to a larger scale.

Fig. 3 is a transverse section on line II--II of Fig. 2. l V Fig. 4 is atransversesection en line lIL-III of Fig. 2. l

In the figures, l indicates the cylinder secured to the crank case 2-surrounding the crankshaft 3 which is connected to the piston 5 by meansof theconnecting rod 4. The cylinder is provided with two inlet ports 6which, at the end of the ascending stroke of the piston, registerwithtwo openings 7 provided at the bottom of the piston skirt. These twoopenings :communicate with the two branches 81 and 82 of the passage 8which is cast into the piston. The branches extend from the bottom endof the piston to about the height of the wrist pin where they are unitedto form the single passage 8 which ends below the piston top. The twobranch passages 81' and 82 leave between themselves a space 9 extendingup to the piston wall,

5 rod asvcan be seen from Figure 3. The crank ton a partial vacuum isformed in the crank` case and ,when the piston arrives near the upperdead center the two openings 7 in the piston are opposite the inletports 6 in the cylinder. Combustible mixture drawn from the carburetor,which is not shown,. through the ports 6, the openings 7, the twobranches 8l and 82, and the passage 8 towards the piston top and fromthere flows downwardly into the crank case 2. During the downward strokeof the piston the charge is compressed in the crank case and after thepiston uncovers the inlet ports 1l flows through the transfer passage l0into the cylinder and drives the burnt gases out through the exhaustports 12 in the well known manner oftwo cycle engines.

-With a construction as described it is possible to use the method ofcooling the piston with combustible mixture even for very small trunktype pistons.

I claim:

In a two cycle internal combustion engine with a crank case scavengingpump, a crank shaft, a cylinder provided with inlet and ex-` haustports, a conduit in the cylinder wall for connecting the crank case withsaid inlet ports, al piston within said cylinder, av connecting rodbetween said piston and said crank shaft, and a passage formed in saidpistou for conducting the combustible mixture into the interior thereofto beneath the piston head, said passagedividing towards the inlet endthereof in two branches adapted to communicate at the end of thecompression stroke of the piston with two crank case inlet ports andleaving a space between each other for the motion of the connecting rod.

In testimony whereof I affix my signature LEON DUFOUR.

is then y

